In humans, oculocutaneous (OCA) albinism is a collection of autosomal recessive disorders characterized by an absence of the pigment melanin in skin, hair, and eyes. That is, normal pigmentation (A) is dominant over albino characteristics (a). For this question, assume it is a single gene with two alleles. If both parents display the albino phenotype, what are all of the possible genotypes that may be observed in their offspring?